1. Field of the Invention
The present invention relates to an exerciser, and more particularly to an exerciser having an improved resistive device for suitably applying resistive forces to against the driving device of the exerciser.
2. Description of the Prior Art
Various kinds of typical exercise apparatus have been developed and comprise a resistive device coupled to a driving device, in order to provide a resistive force against the driving device.
For example, U.S. Pat. No. 2,512,911 to Benice disclose two of the typical exercise machines comprising a coil spring type resistive device received in a drum, to provide the resistive force against a pulling type driving device. The drum of the typical exercise machines do not enclosed or sealed such that no grease or lubrication oil may be received in the drum to lubricate the coil spring.
U.S. Pat. No. 5,916,069 to Wang et al. discloses another typical exercise machine comprising a magnetic resistive device in addition to a coil spring type resistive device, to provide the resistive force against a pulling type driving device. Similar, the coil spring may not be enclosed and sealed within a driving wheel, such that grease or lubrication oil may flow out of the driving wheel.
The present applicant has also developed a typical exercise machine comprising a magnetic resistive device for providing the resistive forces against a cycling exerciser, and disclosed in U.S. Pat. No. 5,916,069 to Liou. However, the typical exercise machine also fail to disclose a resistive device including a coil spring type resistive device in addition to the magnetic resistive device.
U.S. Pat. No. 6,488,611 to Ambrosina et al. discloses a further typical exercise machine comprising a fluid resistance device to provide an impeller actuated resistive force against a driving device. However, a housing is required to be completely sealed to receive the fluid, and to prevent the fluid from flowing out of the housing, such that a complicated water sealing structure is required to be provided or formed in the housing. Furthermore, the typical exercise machine also fail to disclose a resistive device including a coil spring type resistive device received in a fluid tight sealed housing.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional exercisers.